Complex Episodic Explosive Volcanism: Eruption Dynamics of the 1959 Kilauea Iki Eruption, Hawaii

University Of Hawaii, Honolulu

Investigators

Abstract

The 1959 eruption of Kilauea Iki was one of the best-documented basaltic explosive eruptions ever recorded. The highest lava fountains yet recorded for that volcano were observed during this eruption and 16 phases of explosive activity took place over 37 days. However, these fire-fountaining episodes were of irregular length and spacing and accompanied by drainage of lava from and into a newly formed lava lake in the adjacent Kilauea Iki crater. A new logical step in understanding this classical eruption is to move inside the eruption to treat individual eruptive phases or episodes as discrete entities. The primary goal of this project is to complete the documentation of the pyroclastic products of this complex fire-fountaining eruption identifying underlying causes of the episodic nature of the eruption, and the contrasting abundance and dispersal of reticulite-pumice and scoria-spatter in the eruption products. The investigators plan to first refine the database of observations of the rates and nature of cone growth to match to the record of fountain height with time. Secondly, they will map individual beds in the widespread scoria-pumice blanket and assign them to individual eruptive episodes and constrain their dispersal. Finally they will quantify size distributions of bubble and microlite populations in the erupted clasts to constrain contrasting histories of ascent, eruption, and cooling. In terms of broader impacts, a clearer understanding of the triggering mechanisms of Hawaiian basaltic eruptions is of fundamental importance in order to assess hazards of future explosive events at basaltic volcanoes, and to improve understanding of the range of behaviors of these volcanoes. More specifically, the Kilauea Iki 1959 deposits are visited by almost all of the 2.3 million visitors to Hawaii Volcanoes National Park (HVNP) in 2002. It is planned to form a partnership with HVNP using independent funding to develop a range of products and interpretative activities to make this eruption a showcase for visitors. The eruption has already formed the basis for four field workshops for graduate students and features in the annual courses run by the Center for the Study of Active Volcanoes. The results will be widely disseminated via the Internet using linked web sites hosted by Hawaii Volcanoes National Park, Hawaiian Volcano Observatory and University of Hawaii.